Loss of control

The pilot was requested, by the passenger, to land the helicopter on the mud flats to the north of Kununurra. He decided to make a run on landing as he believed he may have difficulty in hovering the helicopter. As the aircraft approached the touchdown point, the pilot allowed it to yaw into wind, but it contacted the ground still moving sideways. The left skid caught in the dry mud and the helicopter rolled onto its side. The pilot was inexperienced in the operation of helicopters and had experienced difficulty in hovering the aircraft when he departed Kununurra that morning. The approach to land on the mud flat was poorly planned and the pilot misjudged the altitude of the aircraft during the turn into wind.

Circumstances:

The purpose of the flight was for the pilot under check to obtain a tailwheel undercarriage endorsement. Prior to take-off, the pilot under check was briefed that due to the instructor's seating position, he was unable to apply full rudder pedal travel. Therefore, rudder control would have to be exercised by the pilot under check. During a demonstrated short field landing by the instructor, the pilot under check did not take control of the rudder on the ground as briefed. Directional control of the aircraft was lost despite calls by the instructor for the pilot to check the swing and use brake. The aircraft left the strip and was substantially damaged. The reason why the pilot under check did not take control of the rudder pedals during the landing was not determined, as he refused to co-operate with the investigation.

The pilot was carrying out a period of solo circuits as part of a check on the aircraft type. Following the third circuit, the aircraft was observed to approach and land normally into the 10 to 15 knot headwind. During the subsequent landing roll, while still travelling at about 30 knots, the aircraft veered suddenly to the left. The pilot applied full right brake and rudder and then both brakes in an attempt to stop the aircraft. However, before the aircraft stopped it struck one of the boundary fence posts. An inspection of the aircraft did not reveal any mechanical defects that could have contributed to the occurrence, and the pilot was unable to explain the reason for the loss of directional control. This accident was not the subject of an on-site investigation.

Whilst mustering cattle near a holding yard, the helicopter was being held in the hover in a 15-20 knot headwind. Because some of the cattle broke away, the pilot turned downwind to herd them back. As the aircraft rolled out of the turn it began to descend and the pilot attempted to arrest the sink by increasing collective. However, the helicopter continued downward and impacted heavily on the ground resulting in the tail boom being sheared off. It then bounced into the air and began to yaw rapidly but the pilot quickly and firmly placed it back onto the ground. When the helicopter came to rest the occupants were able to extricate themselves from the wreckage. The pilot misjudged the performance that could be expected from the helicopter. When the machine was turned downwind, the sudden loss of lift resulted in a descent from which the pilot was unable to recover before the aircraft collided with the ground. The pilot reported that he believes he overpitched the main rotor during the recovery attempt.

The pilot had only recently arrived in the area and had not operated from this strip previously. On his first take-off from the strip he decided to employ a short field technique and lifted the aircraft off the ground at 50 knots. The aircraft became airborne after a ground roll of about 250 metres but after travelling a further 110 metres the wingtip struck the ground, the aircraft landed heavily and ran off the side of the strip. The pilot continued with the attempted take-off and the aircraft travelled a further 325 metres before the take-off was abandoned when the aircraft struck trees. The Pilot's Operating Handbook gives the climb speed after a short field takeoff as 57 knots. The prevailing wind at the time was a crosswind from the right and the pilot believes he may have encountered some tailwind component during the take-off. This combined with a lower than recommended climb speed probably resulted in the aircraft stalling before contacting the ground. After the aircraft had run off the strip it was travelling downwind over soft ground and thus would have required a higher groundspeed than that probably expected by the pilot before it became airborne.

Immediately after take-off the aircraft was seen to enter a steep climbing turn to the left. After turning through about 135 deg, and at an estimated height of 100 to 150 ft agl, the aircraft suddenly pitched nose down and lost height. The aircraft collided with a tree prior to impacting the ground in a nose-low left wing down attitude. The investigation did not reveal any mechanical faults with the aircraft that could have contributed to this accident. The pilot had been flying and working long hours and had been seen to hurry his circuit procedures in the past. On this occasion adequate flying speed was not maintained for the manoeuvre being attempted. The turn after take-off was made into the late afternoon sun and it is possible that the pilot`s vision was affected by sun-glare.

The pilot reported that he was making a landing approach in 10 knot crosswind conditions. After the first touchdown he experienced difficulty in maintaining directional control and elected to carry out a go-around. On the subsequent approach the aircraft touched down prematurely and bounced. While airborne the aircraft commenced to drift to the right, before touching down and bouncing again. A go-around was initiated but the aircraft drifted further to the right and struck a fence 64 metres from the runway centre-line. It was estimated that the wind was actually gusting up to about 20 knots across the runway and was therefore above the maximum crosswind limit for the aircraft type. The pilot had been unable to maintain directional control during the go around and the tailwheel had snagged on the fence.

Circumstances:

The aircraft was to spread 600 Kilograms of nitrate on a local wheat crop. The weather was clear with a gusting 10 knot crosswind/tailwind from the left. Take-off from runway 04 was normal until as the tail was raised a swing developed to the left which could not be corrected by opposite rudder and braking. The aircraft veered off the runway the throttle was closed and the aircraft settled back on three wheels but continued to swing to the left. The pilot concerned he would collide with a levy bank to the left of the strip applied left brake in an attempt to ground loop the aircraft and stop. However, the right mainwheel sank into the soft surface resulting in damage to the right wing tailplane and tailwheel. The pilot later said that the gusting crosswind from the right plus the natural tendency of the aircraft to swing to the left could not be counteracted by opposite rudder and brake.

Circumstances:

With the wind from the right rear quarter at seven knots and 15 degrees of flap selected the pilot attempted a downhill take-off from a one-way 390 metre grass strip. The aircraft was about 100kg below maximum all up weight with the right fuel tank full and the left tank half full. The pilot reported that he flew the aircraft clear of the ground at an indicated airspeed of 50 knots after approximately two thirds of the strip length. Shortly after becoming airborne the stall warning sounded, and the aircraft yawed violently left. The aircraft collided with a fence before coming to a rest about 200 metres from the departure end of the strip. The pilot indicated that the aircraft became airborne at too low an airspeed and that this coupled with the fuel imbalance and the tail wind resulted in a loss of control.

Circumstances:

The pilot reported that after take-off he climbed the aircraft to approximately 500 feet where he levelled out. When he commenced a right turn, he heard a loud "snap" after which the aircraft would not respond to aileron control. The aircraft continued the turn out of control until impact with trees and the ground. The wreckage was examined by a licenced aircraft maintenance engineer who found that the damage to the controls was consistent with impact damage. No evidence of pre-impact damage was found.